Aluminium Sunroom Systems & Prefab Glass Sunroom Kits

What is an aluminium sunroom system?

A sunroom is a single-storey, mostly glazed room built against an existing building. In North American codes it is usually defined as a room where glazing makes up more than about 40 % of the exterior wall and roof area. A sunroom system is the engineered frame and enclosure that makes such a room repeatable: profiles, connectors, seals, glazing and roof panels designed to work together, with tested load and weather performance.

Aluminium dominates this market for practical reasons. A 6063-T6 extrusion is stiff enough to span 3 to 5 m as a roof beam in a section that would look heavy in timber, it can carry internal screw ports, gasket grooves and drainage channels in a single shape, and its oxide film plus a powder or PVDF coating keeps it looking new with nothing more than washing. Steel needs constant protection against corrosion in a room full of condensation, and timber moves with humidity, which breaks glazing seals.

The word "system" matters. A sunroom fails at the joints: where the roof meets the house wall, where rafters meet the front beam, where glazing meets frame and where water leaves the roof. Buying matched profiles, gaskets, flashings and gutters from one source avoids the leaks and condensation problems that come from mixing parts that were never designed together.

Common types of aluminium sunroom

The right type depends on how many months of the year the room will be used, whether it will be heated or cooled, and how much it must keep out insects, rain and noise. North American building codes go further and assign every sunroom to one of five categories under AAMA/NPEA/NSA 2100, which then decides the performance the frame and glazing must prove.

Sunroom categories under AAMA/NPEA/NSA 2100

The International Residential Code (IRC section R301.2.1.1.1) requires sunrooms to comply with AAMA/NPEA/NSA 2100 and requires the designer or owner to state the category on the construction drawings. Even outside North America, these categories are a useful way to agree what a sunroom must achieve before choosing profiles and glass.

Summarised from the IRC and AAMA/NPEA/NSA 2100. In Europe, the windows and doors in a conservatory are assessed to EN 14351-1, and structural loads to the Eurocodes (EN 1990, EN 1991 and EN 1999 for aluminium).

The category has a direct effect on cost. A Category V room is treated much like part of the house: it needs thermally broken framing, insulated glass that meets the local energy code and tested air and water performance. A Category I or II room can use simpler profiles and single glazing. Agree the category at the start, because changing it later means changing almost every component.

Which aluminium alloys and profiles go into a sunroom?

Sunroom frames are extruded almost entirely from 6xxx alloys, which combine good strength after ageing with excellent extrudability and a surface that coats and anodises well. The table shows typical choices; final sections are sized by structural calculation for the local wind and snow loads.

Deflection, not strength, usually controls sunroom design. Aluminium has about one third of the stiffness of steel, so roof beams are sized to limit sag under snow and to keep glass and seals from being overstressed. Deeper sections or internal steel reinforcement are used where spans are long or snow loads are high.

Roof shapes and roofing materials

The roof decides most of a sunroom's comfort: it receives the most sun, carries the snow and handles all of the rain. Pick the shape for the house and the drainage, and the material for the climate.

Building codes in many countries require overhead or sloped glazing to be laminated, or to have a protective screen, so that broken glass is held in place. Check local rules before specifying roof glass.

Glass, screen and wall panel options

Glazing usually covers most of a sunroom's envelope, so it controls heat loss in winter, overheating in summer, glare and safety. These are the common choices and where each fits.

A useful rule is to start from the roof and the sun-facing wall. These two surfaces account for most of the summer heat gain, so they get the best solar-control glass or insulated panels, while shaded walls can use clearer glass for views. Screens can be combined with sliding glass panels so that a three-season room becomes a screen room on warm evenings. For mesh and screen frames see our aluminium window screens page.

Drainage, sealing, insulation and ventilation

Most sunroom complaints are about leaks, condensation, heat and cold. Each one has a design answer that should be built into the system rather than added on site.

• Roof drainage: a continuous fall to an integrated front gutter, with downpipes sized for local rainfall intensity and concealed drainage inside the posts where appearance matters
• Wall connection: a wall plate or wall beam fixed to the house, with a flashing chased into the masonry or lapped under cladding; this is the joint most likely to leak
• Glazing seals: EPDM gaskets in two lines inside and outside the glass, with a drained and ventilated rebate so any water that passes the outer seal escapes
• Condensation channels: glazing bars with internal gutters that collect condensate and lead it to the outside
• Thermal breaks: polyamide strips separating inner and outer aluminium, needed for heated rooms to stop cold frames and condensation
• Ventilation: roof vents, high-level windows and opening doors to purge hot air; a fully glazed room in sun can overheat quickly without them
• Shading: internal blinds, external awnings or aluminium sunshade systems on south- or west-facing rooms

U-values are indicative ranges for the whole window (frame plus glass). Actual values depend on the profile depth, thermal-break width, glass build-up and spacer, and should be taken from tested or calculated data for the specific system.

What goes into an aluminium sunroom

Metline supplies the aluminium parts, such as frame profiles, glazing bars, cover caps, gutters and brackets, to a fabricator who adds glass, doors and panels and assembles locally. Typical components:

Profiles can be cut to length, drilled, punched, milled and notched to drawings before shipping, so the site team bolts parts together rather than measuring and cutting. Each part can be labelled against an assembly drawing and packed in project order, which shortens installation and reduces site errors. For the frame materials themselves, see 6063 extrusions and 6063 square tube.

Colours and surface finishes

Where aluminium sunrooms are used

• Homes and villas: garden rooms, breakfast rooms and lounges built onto the rear of a house
• Hotels and resorts: glass dining rooms, lobbies and lounges that give guests a view in any weather
• Restaurants and cafés: conservatory dining areas and enclosed terraces that add covers all year
• Pool enclosures: glass rooms over or beside a pool, needing corrosion-resistant finishes and good ventilation
• Porch and balcony enclosures: renovation projects that turn an open porch or terrace into usable space
• Care homes, schools and clinics: bright day rooms and waiting areas with good daylight

A typical villa garden room might use a lean-to roof with insulated aluminium panels and two glass strips, Low-E double-glazed walls on thermally broken 6063 frames and a three-panel sliding door, giving daylight without overheating. A café terrace, by contrast, might choose a retractable glass roof and stacking glass walls so it can open fully in summer.

How to specify and order sunroom profiles

1. Define the roomPlan size, roof shape, wall heights, door and window positions, and how the room meets the existing building.
2. Set the performanceSeason of use or AAMA 2100 category, target U-values, local wind and snow loads, and any acoustic needs.
3. Choose materialsThermally broken or standard frame, glass build-up, roof material, screens and finish colour.
4. Approve drawingsWe confirm the configuration, profile list and finish; structural calculations are prepared by your project engineer.
5. ShipProfiles cut and machined to drawing, labelled and packed in export cases, with packing lists and mill certificates on EXW, FOB, CIF or DAP terms.

Related outdoor systems and materials

Aluminium (aluminum) sunrooms: frequently asked questions